Localization of hyaluronic acid in synovial cells by radioautography.
Cultured human synovial cells secrete hyaluronic acid (HA) into the culture medium. Glucosamine-6-(3)H was shown to be a direct and relatively specific precursor of HA-(3)H by the following observations: the susceptibility of nondialyzable radioactivity in the medium to hyaluronidase, its migration with hexuronic acid on zone electrophoresis in polyvinyl chloride, its exclusion from Sephadex G-200, and the localization of radioactivity to glucosamine after hydrolysis of the labeled polysaccharide. The presence of intracellular HA-(3)H was established by sequential extraction of labeled cells and by radioautography of synovial cell cultures digested with hyaluronidase in situ. When cells were exposed to medium lacking glucose, glucosamine-(3)H-uptake was enhanced; and this made possible electron microscopic radioautographic studies. These studies demonstrate the early and continued presence of HA-(3)H within the Golgi apparatus.
D001345:Autoradiography; D002854:Chromatography, Paper; D004586:Electrophoresis; D004721:Endoplasmic Reticulum / Q000378:metabolism; D005944:Glucosamine / Q000378:metabolism; D006056:Golgi Apparatus / Q000032:analysis; D006651:Histocytochemistry; D006801:Humans; D006820:Hyaluronic Acid / Q000032:analysis* / Q000378:metabolism; D006821:Hyaluronoglucosaminidase / Q000378:metabolism; D008297:Male; D008854:Microscopy, Electron; D008928:Mitochondria / Q000378:metabolism; D013583:Synovial Membrane / Q000032:analysis* / Q000378:metabolism; D013737:Testis / Q000201:enzymology; D014316:Tritium
D014316:Tritium; D006820:Hyaluronic Acid; D006821:Hyaluronoglucosaminidase; D005944:Glucosamine